Conservative treatment of guttural pouch mycosis in a Hungarian sport horse mare

Background: Guttural pouch mycosis is an uncommon disease in horses, nevertheless it can lead to life threatening conditions. To date it is unclear with predisposing :lectors lead to the development of the fungal infection. Some hypotheses suggest that viral or bacterial infections, immunosuppression, antibiotic or corticosteroid treatment can play a role in the pathogenesis. Objectives: Our goal was to describe the pathophysiology, differential diagnosis, different conservative treatment options, and the importance of upper airway endoscopy in guttural pouch mycosis. Materials and Methods: A 16 years old Hungarian sport horse mare was examined because of chronic, unilateral purulent nasal discharge. During respiratory endoscopy, bilateral guttural pouch mycosis was diagnosed. The mare was treated conservatively with nystatin powder. Results and Discussion: The mare had a history of unilateral purulent nasal discharge for six weeks, left sided Horner's syndrome, and conjunctivitis. Prior to presentation. the mare had been administered several courses of antibiotics and nonsteroidal anti-inflammatory medications. Vital parameters were within normal limits. During the respiratory workup, severe, bilateral guttural pouch mycosis was diagnosed. There was no history of epistaxis. The horse was treated conservatively, the plaques were debrided, the pouches were lavaged with Saline, and nystatin powder was administered to each guttural pouch. Microbiology revealed Aspergillus fumigatus as the dominant pathogen, which was sensitive to nystatin. A fistula was formed on the medial septum between the two guttural pouches. After 63 days, the mare was discharged from the hospital. Ptosis of the left upper eyelid was present after 6 months. Nystatin powder can be a good firs: choice in the treatment of guttural pouch mycosis. However, it must be emphasised that careful cased selection is of utmost importance